The latest details on the scare in the sky overnight. An alaska airlines pilot lost consciousness in midair and collapsed right in front of the passengers. Neal karlinsky has been tracking this all night. Reporter: When the plane landed here in portland overnight, it was met by emergency cruise and lots of questions. How could the pilot suddenly pass out with 116 passengers on board depending on him in the middle of a flight. There's the -- Reporter: If it sounts matter of fact, the scene in the cockpit was anything but. The pilot looses consciousness mid flight. 121 souls on board and approximately 10,000 pounds of fuel. Reporter: It took off from los angeles at 6:30 p.M. Due to land in seattle at 9:30. Portland international said we received a report around 8:50 that an alaska airlines flight was en route to portland because one of the pilots passed out. A passenger said the pilot opened the cabin door and collapsed into the aisle. The copilot took control of the plane, while a doctor on board attended to the captain. It is very rare that we have a pilot pass out, lose consciousness or have a physical impairment in the cockpit. When it does happen, that's the reason we have two people up there very well trained. Reporter: John nance is an abc news consultant and a former pilot for alaska airlines. Your first job if the captain should keel over is to fly the airplane. Number one. And try to revive him and figure out what is going on when you can. Reporter: The plane landed safely and was met by paramedics. Passengers were put on another flight that made to it seattle overnight. The pilot was taken to the hospital. The pilot has been flying for them for 28 years. No word on the medical problem. The first officer is very experienced. He's been flying for alaska for 11 years. Still a lot of questions here, george. Sure are. Must have been so scary to see that pilot go down. And the airline saying it's a pre-existing medical condition. Why with that are you flying a commercial airplane? More questions to be answers for sure.

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